It comes as no surprise to me that you can't get one specialist to enter into any arrangement where they will publically criticize one of their colleagues. They stick together like shit sticks to blankets.
This is the major barrier to any legal action against them. If you can afford to pay one of them to act as an expert witness in court, you may have half a chance of getting one on board, but that constitutes a huge financial risk for you---that cost is certainly not covered in any 'No win, no fee' arrangements. Be very sure you know what is covered if you head down that track, Cate.